Heat sensitive shut-off valve



July 7, 1959 H. F. NORDAHL 2,893,413

HEAT SENSITIVE SHUT-OFF VALVE Filed July 2, 1957 Fig. 2

Hora/a F. Noroa/a/ INVENTOR. BY MW,

2,893,413 Patented July 7, 1959 2,893,413 HEATSENSITIVESHUT-OFF VALVE Harold F. Nordahl, Columbus, Mont. Application July 2,1957, Serial Na. 669,489 4 Claims. (Cl. 137-75 The present invention generally relates to a valve construction and more particularly to a safety valve especially adapted for use in the supply line from a source of fuel to a heating unit so that the flow of fuel will be stopped if the unit operates beyond a predetermined safe temperature.

Quite often, the regular controls provided for heating units of various types become inoperative due to mechanical failure, dirt, corrosion or for many other purposes. This failure quite often results in the heating unit operating beyond certain safety limits and sometimes causes damage to the heating unit and also to surrounding areas, such as when a boiler may explode or become warped or otherwise destroyed from overheating. Accordingly, it is the primary object of the present invention to provide a shut-off valve operable in response to a predetermined temperature so that the heating unit will be rendered inoperative if this temperature is exceeded.

Another object of the present invention is to provide a safety shut-off valve having a replaceable unit in the form of a bellows type diaphragm having a tube connected thereto, with the tube having a fusible plug therein, with the fusible plug being disposed at the point of heat sensitivity, with the diaphragm working against a spring urged valve member which will automatically close if the pressure in the diaphragm is released in the event the fusible plug is melted.

Other objects of the present invention will reside in its simplicity of construction, ease of operation, adaptation for various purposes, safety, and its relatively inexpensive manufacturing cost.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a perspective view of the valve of the present invention;

Figure 2 is a longitudinal sectional view taken substantially upon a plane passing through the longitudinal center of the valve of the present invention; and

Figure 3 is a transverse, plan sectional view taken substantially upon a plane passing along section line 3-3 of Figure 2 illustrating the details of construction of the valve member.

Referring now specifically to the drawings, the numeral generally designates the valve of the present invention which includes a generally semi-spherical, hollow valve body 12 having oppositely disposed bosses 14 and 16 respectively which are internally threaded as designated by numeral 18, with the boss 14 forming an inlet and the boss 16 forming an outlet. The interior of the valve body is hollow, as indicated by numeral 20, and is provided with an inwardly extending, tubular portion 22 forming a continuation of the outlet 16. Extending in perpendicular relation to the tubular portion 22 is a vertically disposed, tubular member 24 in communication with the tubular portion 22 and terminating at its lower end in a valve seat 26.

A removable, hollow, frusto-conical valve cover 28 is provided and is retained in position on the valve body 12 by a series of fastening bolts 30. The valve cover 28 is provided with a socket or recess 32 receiving a compression coil spring 34 having a follower plate 36 atthe upper end thereof, with the follower plate 36 having a projecting threaded stud 38 having a semi-spherical valve 40 secured thereon by a fastening nut 42. The free end of the stud 38 is provided with an inwardly extending recess 44 for receiving the pointed end 50 of a solid tip on a'bellows type diaphragm 52 disposed within the tubular portion 24. The upper end of the diaphragm 52 is provided with a hollow fitting 54 which is externally threaded as indicated by numeral 56 for receiving a nut 58 which engages the outside of the valve body 12 and seals the diaphragm thereto, with the upper end of the diaphragm 52 having a sealing gasket 60 disposed between the body and itself. The tubular member 54 is connected to an elongated, curved tube 62 which may be of any suitable construction and which may be of any suitable length, with the tube 62 having a fusible plug or fusible end 64 disposed at the desired point in order to sense the heat or temperature at that particular point. In the event the temperature at that particular point exceeds the melting point of the material from which the fusible plug is constructed, then the fusible plug will be melted and the charge of material in the diaphragm and tube will be released, thus releasing the diaphragm 52 so that the same may collapse and the spring 34 will then urge the valve 40 against the valve seat 26 for stopping the flow of fuel to the heating unit. The semi-spherical shape of the valve 40 will prevent any foreign material from lodging thereon during normal operation, thereby providing a positive seal for the valve 46. The diaphragm and thermostatic tube may be filled with any suitable liquid, gas or air charge to overcome the spring pressure on the valve disk 40, thereby holding the valve disk open until such time as the temperature at the location of the fusible plug 64 reaches the melting point, thus releasing the pressure and allowing the spring to close the valve.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A heat sensitive valve comprising a hollow body having an inlet and an outlet, an inwardly extending tnbular portion forming said outlet, a tubuuar member extending perpendicular to said tubular portion in intersection and communicating relation to the inner end thereof, said tubular member extending beyond the inner end of the tubular portion and terminating in an open valve seat communicating with the inlet, a valve disk movably mounted in said body, spring means between the body and disk for urging the disk towards the valve seat, an inflatable bellows disposed in said tubular member and having one end engaged with said disk with the other end connected with a fitting extending through the body wall, an elongated tube connected with said fitting, and a fusible area forming a portion of said tube and forming a closure for the tube and bellows for retaining the bellows in inflated condition and holding the disk away from the valve seat whereby rupture of the fusible area by overheating will deflate the bellows for permitting collapse thereof and movement of the disk stopping flow through the valve.-

onto the valve seat for 2. The combination of claim 1 wherein said valve disk is provided with a conical socket for constantly receiving a rigid conical tip onsaid bellows for retaining the valve and bellows in alignment.

3. The combination of claim 2 wherein said valve disk is provided with a convex surface facing the valve seat for preventing deposit of foreign material on said valve disk.

4. A valve comprising a valve body having an inlet and an outlet and a valve seat therebetween, a valve member reciprocally mounted in said body for seating upon said seat, a spring disposed between the valve member and body for urging the valve member towards the valve seat, an inflated bellows type diaphragm mounted in said body and having a free end engaging said valve member in opposition to said spring and holding the valve member away from the seat while compressing the spring thereby permitting flow through the body, a tube connected to the bellows type diaphragm and extending exteriorly of the body, and a fusible element in said tube for location in a predetermined area whereby temperature in the area above the melting point of the fusible element causes the fusible element to disrupt thereby deflating the bellows type diaphragm thereby retracting the free end thereof permitting the spring to move the valve member towards the valve seat'for preventing flow from the inlet to the outlet.

References Cited in the file of this patent UNITED STATES PATENTS 829,458 Brown Aug. 28, 1906 962,648 Miller June 28, 1910 2,673,707

McRae Mar. 30, 1954 

